Document and Entity Information	12 Months Ended
Document and Entity Information	Dec. 31, 2018 shares
Document And Entity Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Trading Symbol	JG
Entity Registrant Name	Aurora Mobile Ltd
Entity Central Index Key	0001737339
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Class A Common Shares
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	59,547,823
Class B Common Shares
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	17,000,189

CONSOLIDATED BALANCE SHEETS ¥ in Thousands, $ in Thousands	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 CNY (¥)
Current assets:
Cash and cash equivalents	¥ 576,562	$ 83,857	¥ 208,161
Restricted cash	115	17	115
Accounts receivable, net of allowances of RMB3,462 and RMB9,308 (US$1,354) as of December 31, 2017 and 2018, respectively	141,911	20,640	49,594
Prepayments and other current assets	80,578	11,719	34,228
Amounts due from related parties	4,564	664	1,260
Total current assets	803,730	116,897	293,358
Non-current assets:
Property and equipment, net	92,874	13,508	53,023
Intangible assets, net	1,531	223	283
Long-term investments	79,696	11,591	10,980
Other non-current assets	14,237	2,071	1,806
Total non-current assets	188,338	27,393	66,092
Total assets	992,068	144,290	359,450
Current liabilities:
Accounts payable (including accounts payable of the variable interest entity (“VIE”) without recourse to the Company of RMB8,340 and RMB18,683 (US$2,717) as of December 31, 2017 and 2018, respectively)	18,811	2,736	8,340
Deferred revenue and customer deposits (including deferred revenue and customer deposits of the VIE without recourse to the Company of RMB48,085 and RMB55,625 (US$8,091) as of December 31, 2017 and 2018, respectively)	59,483	8,651	49,557
Accrued liabilities and other current liabilities (including accrued liabilities and other current liabilities of the VIE without recourse to the Company of RMB31,631 and RMB59,556 (US$8,662) as of December 31, 2017 and 2018, respectively)	76,666	11,151	52,639
Amounts due to related parties (including amount due to related parties of the VIE without recourse to the Company of RMB459 and RMB8,864 (USD$1,289) as of December 31, 2017 and 2018, respectively)	8,864	1,289	6,110
Total current liabilities	163,824	23,827	116,646
Non-current liabilities:
Other non-current liabilities (including other non-current liabilities of the VIE without recourse to the Company of RMB216 and RMB140 (US$20) as of December 31, 2017 and 2018, respectively)	140	20	216
Deferred tax liabilities (including deferred tax liabilities of the VIE without recourse to the Company of RMB5 and RMB nil (US$ nil) as of December 31, 2017 and 2018, respectively)			5
Deferred revenue (including deferred revenue of the VIE without recourse to the Company of RMB330 and RMB nil (US$ nil) as of December 31, 2017 and 2018, respectively)	10,265	1,493	330
Convertible notes (including deferred revenue of the VIE without recourse to the Company of RMB nil and RMB nil (US$ nil) as of December 31, 2017 and 2018, respectively)	216,179	31,442	0
Total non-current liabilities	226,584	32,955	551
Total liabilities	390,408	56,782	117,197
Commitments and contingencies
Mezzanine equity
Total mezzanine equity			466,637
Shareholders’ (deficit) equity
Common shares			26
Treasury shares (nil and 46,303 class A common shares as of December 31, 2017 and 2018, respectively)	(3,165)	(460)
Additional paid-in capital	944,500	137,372	13,689
Accumulated deficit	(348,123)	(50,632)	(234,810)
Accumulated other comprehensive loss	8,400	1,221	(3,289)
Total shareholders’ (deficit) equity	601,660	87,508	(224,384)
Total liabilities, mezzanine equity and shareholders’ deficit	992,068	144,290	359,450
Series A Contingently Redeemable Convertible Preferred Shares
Mezzanine equity
Total mezzanine equity			26,979
Series B Contingently Redeemable Convertible Preferred Shares
Mezzanine equity
Total mezzanine equity			52,723
Series C Contingently Redeemable Convertible Preferred Shares
Mezzanine equity
Total mezzanine equity			168,317
Series D Contingently Redeemable Convertible Preferred Shares
Mezzanine equity
Total mezzanine equity			¥ 218,618
Class A Common Shares
Shareholders’ (deficit) equity
Common shares	37	5
Class B Common Shares
Shareholders’ (deficit) equity
Common shares	¥ 11	$ 2

CONSOLIDATED BALANCE SHEETS (Parenthetical) ¥ in Thousands, $ in Thousands	Dec. 31, 2018 CNY (¥) shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 CNY (¥) shares
Accounts receivable, net of allowances	¥ 9,308	$ 1,354	¥ 3,462
Accounts payable	18,811	2,736	8,340
Deferred revenue and customer deposits	33,067	4,809	28,921
Accrued liabilities and other current liabilities	76,666	11,151	52,639
Amount due to related parties	8,864	1,289	6,110
Other non-current liabilities	140	20	216
Deferred tax liabilities \| ¥			5
Deferred revenue	10,265	1,493	330
Convertible notes (including deferred revenue of the VIE without recourse to the Company of RMB nil and RMB nil (US$ nil) as of December 31, 2017 and 2018, respectively)	¥ 216,179	$ 31,442	¥ 0
Common shares, par value per share \| $ / shares		$ 0
Common shares, shares authorized	50,000,000	50,000,000	470,393,343
Common shares, shares issued	0	0	42,666,670
Common shares, shares outstanding	0	0	42,666,670
Series A Contingently Redeemable Convertible Preferred Shares
Contingently redeemable convertible preferred shares, par value per share \| $ / shares		$ 0
Contingently redeemable convertible preferred shares, shares authorized	0	0	11,111,120
Contingently redeemable convertible preferred shares, shares issued	0	0	11,111,120
Contingently redeemable convertible preferred shares, shares outstanding	0	0	11,111,120
Series B Contingently Redeemable Convertible Preferred Shares
Contingently redeemable convertible preferred shares, par value per share \| $ / shares		$ 0
Contingently redeemable convertible preferred shares, shares authorized	0	0	7,936,510
Contingently redeemable convertible preferred shares, shares issued	0	0	7,936,510
Contingently redeemable convertible preferred shares, shares outstanding	0	0	7,936,510
Series C Contingently Redeemable Convertible Preferred Shares
Contingently redeemable convertible preferred shares, par value per share \| $ / shares		$ 0
Contingently redeemable convertible preferred shares, shares authorized	0	0	4,999,540
Contingently redeemable convertible preferred shares, shares issued	0	0	4,999,540
Contingently redeemable convertible preferred shares, shares outstanding	0	0	4,999,540
Series D Contingently Redeemable Convertible Preferred Shares
Contingently redeemable convertible preferred shares, par value per share \| $ / shares		$ 0
Contingently redeemable convertible preferred shares, shares authorized	0	0	5,559,487
Contingently redeemable convertible preferred shares, shares issued	0	0	5,559,487
Contingently redeemable convertible preferred shares, shares outstanding	0	0	5,559,487
Class A Common Shares
Common shares, par value per share \| $ / shares		$ 0.0001
Common shares, shares authorized	4,920,000,000	4,920,000,000	0
Common shares, shares issued	59,547,823	59,547,823	0
Common shares, shares outstanding	59,547,823	59,547,823	0
Class B Common Shares
Common shares, par value per share \| $ / shares		$ 0.0001
Common shares, shares authorized	30,000,000	30,000,000	0
Common shares, shares issued	17,000,189	17,000,189	0
Common shares, shares outstanding	17,000,189	17,000,189	0
VIE
Accounts payable	¥ 18,683	$ 2,717	¥ 8,340
Deferred revenue and customer deposits	55,625	8,091	48,085
Accrued liabilities and other current liabilities	59,556	8,662	31,631
Amount due to related parties	8,864	1,289	459
Other non-current liabilities	140	20	216
Deferred tax liabilities	0	0	5
Deferred revenue	0	0	330
Convertible notes (including deferred revenue of the VIE without recourse to the Company of RMB nil and RMB nil (US$ nil) as of December 31, 2017 and 2018, respectively)	¥ 0	$ 0	¥ 0

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 CNY (¥) ¥ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 CNY (¥) ¥ / shares shares	Dec. 31, 2016 CNY (¥) ¥ / shares shares
Revenues (including related party amounts of RMB3,507 and RMB2,543 (US$370) for the years ended December 31, 2017 and 2018, respectively)	¥ 714,141	$ 103,868	¥ 284,709	¥ 70,322
Cost of revenues (including related party amounts of RMB788 and RMB19,763 (US$2,874) for the years ended December 31, 2017 and 2018, respectively)	(517,074)	(75,205)	(213,370)	(47,722)
Gross profit	197,067	28,663	71,339	22,600
Operating expenses
Research and development (including related party amounts of RMB762 and RMB200 (US$29) for the years ended December 31, 2017 and 2018, respectively)	(134,358)	(19,542)	(71,651)	(33,717)
Sales and marketing (including related party amounts of RMB541 and RMB178 (US$26) for the years ended December 31, 2017 and 2018, respectively)	(83,853)	(12,196)	(59,673)	(33,062)
General and administrative (including related party amounts of RMB138 and RMB59 (US$9) for the years ended December 31, 2017 and 2018, respectively)	(71,641)	(10,419)	(32,431)	(13,480)
Total operating expenses	(289,852)	(42,157)	(163,755)	(80,259)
Loss from operations	(92,785)	(13,494)	(92,416)	(57,659)
Foreign exchange (loss)/ gain, net	264	38	(2,724)	(328)
Interest income	3,657	532	314	283
Interest expense	(7,054)	(1,026)	(122)
Other income	8,449	1,229	677	232
Change in fair value of derivative liability	21,302	3,098
Loss before income taxes	(66,167)	(9,623)	(94,271)	(57,472)
Income tax (expense) benefit	(30)	(4)	3,980	(3,910)
Net loss	(66,197)	(9,627)	(90,291)	(61,382)
Net loss attributable to Aurora Mobile Limited’s shareholders	(66,197)	(9,627)	(90,291)	(61,382)
Accretion of contingently redeemable convertible preferred shares	(24,094)	(3,504)	(26,391)	(12,427)
Net loss attributable to common shareholders	(90,291)	(13,131)	¥ (116,682)	¥ (73,809)
Net loss per share for class A and class B common shares:
Common shares - basic and diluted \| ¥ / shares			¥ (2.73)	¥ (1.73)
Shares used in net loss per share computation:
Common shares - basic and diluted			42,666,670	42,666,670
Other comprehensive income (loss)
Foreign currency translation adjustments	11,688	1,700	¥ (7,563)	¥ 1,896
Total other comprehensive income (loss), net of tax	11,688	1,700	(7,563)	1,896
Total comprehensive loss	(54,509)	(7,927)	(97,854)	(59,486)
Comprehensive loss attributable to Aurora Mobile Limited	(54,509)	(7,927)	¥ (97,854)	¥ (59,486)
Class A Common Shares
Operating expenses
Net loss attributable to Aurora Mobile Limited’s shareholders	(46,606)	(6,779)
Accretion of contingently redeemable convertible preferred shares	(16,963)	(2,467)
Net loss attributable to common shareholders	¥ (63,569)	$ (9,246)
Net loss per share for class A and class B common shares:
Common shares - basic and diluted \| (per share)	¥ (1.57)	$ (0.23)
Shares used in net loss per share computation:
Common shares - basic and diluted	40,441,999	40,441,999
Class B Common Shares
Operating expenses
Net loss attributable to Aurora Mobile Limited’s shareholders	¥ (19,591)	$ (2,848)
Accretion of contingently redeemable convertible preferred shares	(7,131)	(1,037)
Net loss attributable to common shareholders	¥ (26,722)	$ (3,885)
Net loss per share for class A and class B common shares:
Common shares - basic and diluted \| (per share)	¥ (1.57)	$ (0.23)
Shares used in net loss per share computation:
Common shares - basic and diluted	17,000,189	17,000,189

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 CNY (¥)
Statement Of Income And Comprehensive Income [Abstract]
Revenues - related parties	¥ 2,543	$ 370	¥ 3,507
Cost of revenues - related party	19,763	2,874	788
Research and development - related party	200	29	762
Sales and Marketing - related party	178	26	541
General and administrative - related party	¥ 59	$ 9	¥ 138

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' DEFICIT ¥ in Thousands, $ in Thousands	CNY (¥)	USD ($)	Common Stock CNY (¥) shares	Common Stock USD ($) shares	Treasury Stock CNY (¥)	Treasury Stock USD ($)	Additional Paid-in Capital CNY (¥)	Additional Paid-in Capital USD ($)	Accumulated Other Comprehensive Income CNY (¥)	Accumulated Other Comprehensive Income USD ($)	Accumulated Deficit CNY (¥)	Accumulated Deficit USD ($)
Balance at Dec. 31, 2015	¥ (40,204)		¥ 26				¥ 1,711		¥ 2,378		¥ (44,319)
Balance, Shares at Dec. 31, 2015 \| shares			42,666,670	42,666,670
Net loss attributable to Aurora Mobile Limited’s shareholders	(61,382)										(61,382)
Other comprehensive loss	1,896								1,896
Contribution from shareholder	1,000						1,000
Accretion of contingently redeemable convertible preferred shares	(12,427)										(12,427)
Share-based compensation	2,703						2,703
Balance at Dec. 31, 2016	(108,414)		¥ 26				5,414		4,274		(118,128)
Balance, Shares at Dec. 31, 2016 \| shares			42,666,670	42,666,670
Net loss attributable to Aurora Mobile Limited’s shareholders	(90,291)										(90,291)
Other comprehensive loss	(7,563)								(7,563)
Accretion of contingently redeemable convertible preferred shares	(26,391)										(26,391)
Share-based compensation	8,275						8,275
Balance at Dec. 31, 2017	(224,384)		¥ 26				13,689		(3,289)		(234,810)
Balance, Shares at Dec. 31, 2017 \| shares			42,666,670	42,666,670
Net loss attributable to Aurora Mobile Limited’s shareholders	(66,197)	$ (9,627)									(66,197)
Other comprehensive loss	11,689								11,689
Issuance of Class A common shares in connection with initial public offering	464,380		¥ 4				464,376
Issuance of Class A common shares in connection with initial public offering, Shares \| shares			6,059,708	6,059,708
Conversion of all outstanding contingently redeemable convertible preferred shares to Class A common shares	401,691		¥ 18				357,222				44,451
Conversion of all outstanding contingently redeemable convertible preferred shares to Class A common shares, Shares \| shares			27,867,937	27,867,937
Redemption of contingently redeemable convertible preferred shares	(6,915)										(6,915)
Accretion of contingently redeemable convertible preferred shares							84,652				(84,652)
Repurchased shares	(3,165)				¥ (3,165)
Repurchased shares, Shares \| shares			(46,303)	(46,303)
Share-based compensation	24,561						24,561
Balance at Dec. 31, 2018	¥ 601,660	$ 87,508	¥ 48	$ 7	¥ (3,165)	$ (460)	¥ 944,500	$ 137,372	¥ 8,400	$ 1,222	¥ (348,123)	$ (50,632)
Balance, Shares at Dec. 31, 2018 \| shares			76,548,012	76,548,012

CONSOLIDATED STATEMENTS OF CASH FLOWS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 CNY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 CNY (¥)	Dec. 31, 2016 CNY (¥)
Cash flows from operating activities:
Net loss	¥ (66,197)	$ (9,627)	¥ (90,291)	¥ (61,382)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	18,084	2,630	8,805	3,433
Amortization of intangible assets	307	45	35	0
Unrealized exchange (gain) loss	11,689	1,700	339	(369)
Allowance for doubtful accounts	5,846	850	2,427	1,049
Deferred tax expense (benefit)	(5)	(1)	(3,980)	3,910
Share-based compensation	24,561	3,572	8,275	2,703
Changes in operating assets and liabilities,
Accounts receivable	(98,163)	(14,278)	(48,266)	(5,870)
Prepayments and other current assets	(46,350)	(6,741)	(21,558)	(11,233)
Amounts due from related parties	(3,303)	(480)	(1,169)	(65)
Other non-current assets	(1,431)	(208)	(492)
Accounts payable	10,471	1,523	13,015	822
Deferred revenue and customer deposits	19,861	2,889	31,144	11,018
Accrued liabilities and other current liabilities	24,027	3,495	26,503	14,469
Amounts due to related parties	2,754	401	(243)	676
Change in deferred tax liabilities	(5)	(1)
Other non-current liabilities	(76)	(11)	(76)	(1,313)
Net cash used in operating activities	(97,925)	(14,241)	(75,532)	(42,152)
Cash flows from investing activities:
Purchase of time deposits				(10,000)
Proceeds from maturity of time deposits			10,053
Increase in long-term prepayment	(11,000)	(1,600)
Purchase of long-term investment	(68,716)	(9,994)	(10,000)	(1,041)
Purchase of property and equipment	(57,934)	(8,426)	(28,378)	(18,887)
Purchase of intangible assets	(1,556)	(226)	(319)
Net cash used in investing activities	(139,206)	(20,246)	(28,644)	(29,928)
Cash flows from financing activities:
Proceeds from issuance of contingently redeemable convertible preferred shares, net of issuance cost	216,179	31,442	217,446	134,348
Proceeds from initial public offering, net of issuance cost	464,380	67,541
Redemption of contingently redeemable convertible preferred shares	(62,510)	(9,092)
Repurchase of ordinary shares	(3,165)	(460)
Contribution from shareholder				1,000
Net cash provided by financing activities	614,884	89,431	217,446	135,348
Effect of exchange rate on cash and cash equivalents and restricted cash	(9,352)	(1,362)	(8,282)	2,450
Net increase in cash and cash equivalents and restricted cash	368,401	53,582	104,988	65,718
Cash, cash equivalents and restricted cash at the beginning of year	208,276	30,292	103,288	37,570
Cash and cash equivalents at the beginning of the year	208,161	30,276	103,168	37,570
Restricted cash at the beginning of the year	115	17	120
Cash, cash equivalents and restricted cash at the end of year	576,677	83,874	208,276	103,288
Cash and cash equivalents at the end of the year	576,562	83,857	208,161	103,168
Restricted cash at the end of the year	115	17	115	¥ 120
Supplemental disclosures of cash flow information:
Interest expense paid			122
Purchase of property and equipment included in accrued liabilities and other current liabilities	¥ 104	$ 15	¥ 9,731

Organization and Principal Activities

12 Months Ended

Dec. 31, 2018

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Principal Activities

1	Organization and principal activities

Aurora Mobile Limited (the “Company” and where appropriate, the term “Company” also refers to its subsidiaries and variable interest entity) is a limited company incorporated in the Cayman Islands under the laws of the Cayman Islands on April 9, 2014. The Company, through its subsidiaries and variable interest entity (“VIE”), are principally engaged in providing data solutions which include targeted marketing, industry insights, financial risk management and location-based intelligence services in the People’s Republic of China (the “PRC”).

As PRC laws and regulations prohibit and restrict foreign ownership of internet value-added businesses, the Company operates its business, primarily through the VIE. The Company, through JPush Information Consulting (Shenzhen) Co., Ltd. (“Shenzhen JPush” or “WFOE”) entered into powers of attorney and an exclusive option agreement with the nominee shareholders of the VIE, that gave WFOE the power to direct the activities that most significantly affect the economic performance of the VIE and to acquire the equity interests in the VIE when permitted by the PRC laws, respectively. In addition, pursuant to the supplementary agreements signed in March, 2018, the rights under the aforementioned power of attorney and the exclusive call option agreements were assigned to the board of directors of the Company (the “Board”) or any officer authorized by the Board, which entitled the Company to receive economic benefits from the VIE that potentially could be significant to the VIE.

Despite the lack of technical majority ownership, the Company has effective control of the VIE through a series of VIE agreements and a parent-subsidiary relationship exists between the Company and the VIE. Through the VIE agreements and the supplementary agreements, the shareholders of the VIE effectively assigned all of their voting rights underlying their equity in the VIE to the Company. In addition, through the exclusive business operation agreement, the Company, through its WFOE in the PRC, have the right to receive economic benefits from the VIE that potentially could be significant to the VIE. Lastly, through the financial support agreement and the shareholder voting proxy agreement, the Company has the obligation to absorb losses of the VIE that could potentially be significant to the VIE. Therefore, the Company is considered the primary beneficiary of the VIE and consolidates the VIE as required by SEC Regulation S-X Rule 3A-02 and Accounting Standards Codification (“ASC”) 810.

The following is a summary of the VIE agreements:

Exclusive Option Agreements

Pursuant to the exclusive option agreements entered into between VIE’s nominee shareholders and the WFOE, the nominee shareholders irrevocably granted the WFOE an option to request the nominee shareholders to transfer or sell any part or all of its equity interests in the VIE, or any or all of the assets of the VIE, to the WFOE, or their designees. The purchase price of the equity interests in the VIE is equal to the minimum price required by PRC law. Without the WFOE’s prior written consent, the VIE and its nominee shareholders cannot amend its articles of association, increase or decrease the registered capital, sell or otherwise dispose of its assets or beneficial interest, create or allow any encumbrance on its assets or other beneficial interests and provide any loans or guarantees. The nominee shareholders cannot request any dividends or other form of assets. If dividends or other form of assets were distributed, the nominee shareholders are required to transfer all received distribution to the WFOE or their designees. These agreements are not terminated until all of the equity interest of the VIE is transferred to the WFOE or the person(s) designated by the WFOE. None of the nominee shareholders have the right to terminate or revoke the agreements under any circumstance unless otherwise regulated by law.

Equity Interest Pledge Agreements

Pursuant to the equity interest pledge agreements, each nominee shareholder of the VIE has pledged all of their respective equity interests in the VIE to WFOE as continuing first priority security interest to guarantee the performance of their and the VIE’s obligations under the powers of attorney agreement, the exclusive option agreement and the exclusive business cooperation agreement. WFOE is entitled to all dividends during the effective period of the share pledge except as it agrees otherwise in writing. If VIE or any of the nominee shareholder breaches its contractual obligations, WFOE will be entitled to certain rights regarding the pledged equity interests, including receiving proceeds from the auction or sale of all or part of the pledged equity interests of VIE in accordance with PRC law. None of the nominee shareholders shall, without the prior written consent of WFOE, assign or transfer to any third party, distribute dividends and create or cause any security interest and any liability in whatsoever form to be created on, all or any part of the equity interests it holds in the VIE. This agreement is not terminated until all of the technical support and consulting and service fees have been fully paid under the exclusive business cooperation agreement and all of VIE’s obligations have been terminated under the other controlling agreements. On December 16, 2014, the Company registered the equity pledge with the relevant office of the administration for industry and commerce in accordance with the PRC Property Rights Law.

1	Organization and principal activities (continued)

Exclusive Business Cooperation Agreement

Pursuant to the exclusive business cooperation agreement entered into by WFOE and VIE, WFOE provides exclusive technical support and consulting services in return for an annual service fee based on a certain percentage of the VIE’s audited total operating income, which is adjustable at the sole discretion of WFOE. Without WFOE’s consent, the VIE cannot procure services from any third party or enter into similar service arrangements with any other third party, except for those from WFOE. In addition, the profitable consolidated VIE has granted WFOE an exclusive right to purchase any or all of the business or assets of each of the profitable consolidated VIE at the lowest price permitted under PRC law. This agreement is irrevocable or can only be unilaterally revoked/amended by WFOE.

Powers of Attorney

Pursuant to the powers of attorney signed between VIE’s nominee shareholders and WFOE, each nominee shareholder irrevocably appointed WFOE as its attorney-in-fact to exercise on each shareholder’s behalf any and all rights that each shareholder has in respect of its equity interest in VIE (including but not limited to executing the exclusive right to purchase agreements, the voting rights and the right to appoint directors and executive officers of VIE). This agreement is effective and irrevocable as long as the nominee shareholder remains a shareholder of VIE.

In March 2018, the following supplementary agreements were entered into:

Financial Support Agreement

Pursuant to the financial support undertaking letter dated March 28, 2018, the Company is obligated to provide unlimited financial support to the VIE, to the extent permissible under the applicable PRC laws and regulations. The Company will not request repayment of the loans or borrowings if the VIE or its shareholders do not have sufficient funds or are unable to repay.

Shareholder Voting Proxy Agreement

The Nominee Shareholders also re-signed the powers of attorney agreement whereby they granted an irrevocable proxy of the voting rights underlying their respective equity interests in VIE from the WFOE to the Company, which includes, but are not limited to, all the shareholders’ rights and voting rights empowered to the Nominee Shareholders by the company law and the Company’s Article of Association.

Accordingly, as a result of the power to direct the activities of the VIE pursuant to the powers of attorney agreement and the obligation to absorb the expected losses of VIE through the unlimited financial support, the WFOE ceased to be the primary beneficiary and the Company became the primary beneficiary of the VIE on March 28, 2018.

In the opinion of the Company’s legal counsel, (i) the ownership structure of the PRC subsidiary and the VIE are in compliance with the existing PRC laws and regulations; (ii) each of the VIE agreements is valid, binding and enforceable in accordance with its terms and applicable PRC laws or regulations and will not violate applicable PRC laws or regulations in effect; and (iii) are valid in accordance with the articles of association of the Company.

However, uncertainties in the PRC legal system could cause the Company’s current ownership structure to be found in violation of existing and/or future PRC laws or regulations and could limit the Company’s ability to enforce its rights under these contractual arrangements. Furthermore, the nominee shareholders of the VIE may have interests that are different than those of the Company, which could potentially increase the risk that they would seek to act contrary to the terms of the contractual agreements with the VIE.

In addition, if the current structure or any of the contractual arrangements is found to be in violation of any existing or future PRC laws or regulations, the Company could be subject to penalties, which could include, but not be limited to, revocation of business and operating licenses, discontinuing or restricting business operations, restricting the Company’s right to collect revenues, temporary or permanent blocking of the Company’s internet platforms, restructuring of the Company’s operations, imposition of additional conditions or requirements with which the Company may not be able to comply, or other regulatory or enforcement actions against the Company that could be harmful to its business. The imposition of any of these or other penalties could have a material adverse effect on the Company’s ability to conduct its business.

1	Organization and principal activities (continued)

The following table set forth the assets and liabilities of the VIE included in the Company’s consolidated balance sheets:

	As of December 31,
	2017		2018
	RMB		RMB		US$
ASSETS:
Current assets:
Cash and cash equivalents		49,853		31,763		4,620
Restricted cash		115		115		17
Accounts receivable		49,561		141,705		20,609
Prepayments and other current assets		29,637		64,532		9,386
Amounts due from the Company and its subsidiaries		3,806		3,965		577
Amounts due from related parities		1,186		2,848		414
Total current assets		134,158		244,928		35,623
Non-current assets:
Long-term investments		10,000		71,512		10,401
Other receivables-non current		1,354		2,529		368
Property and equipment, net		24,258		46,271		6,730
Intangible assets, net		283		1,406		204
Long-term prepayment		—		11,000		1,600
Total non-current assets		35,895		132,718		19,303
Total assets		170,053		377,646		54,926
LIABILITIES:
Current liabilities:
Accounts payable		8,340		18,683		2,717
Deferred revenue and customer deposits		48,085		55,625		8,091
Accrued liabilities and other current liabilities		31,631		59,556		8,662
Amounts due to the Company and its subsidiaries		39,861		15,534		2,259
Amounts due to related parties		459		8,864		1,289
Total current liabilities		128,376		158,262		23,018
Non-current liabilities:
Amounts due to the Company and its subsidiaries		60,000		240,000		34,907
Other non-current liabilities		216		140		20
Deferred tax liabilities		5		—		—
Deferred revenue and customer deposits		330		—		—
Total non-current liabilities		60,551		240,140		34,927
Total liabilities		188,927		398,402		57,945

1	Organization and principal activities (continued)

The table sets forth the results of operations and cash flows of the VIE included in the company’s consolidated statements of comprehensive loss and cash flows.

	As of December 31,
	2016			2017			2018
	RMB			RMB			RMB			US$
Revenues		70,148			284,348			709,594			103,206
Cost of revenues		(47,559	)		(206,789	)		(499,589	)		(72,662	)
Net income/(loss)		18,681			(40,003	)		(16,785	)		(2,441	)
Net cash used in operating activities		7,590			(51,016	)		(68,316	)		(9,936	)
Net cash used in investing activities		—			(10,000	)		(104,675	)		(15,224	)
Net cash provided by financing activities		1,000			—			154,901			22,529

There were no pledges or collateralization of the VIE’s assets as of December 31, 2017 and 2018. The amount of net liabilities of the VIE was RMB 18,874 and RMB 20,756 (US$3,019) as of December 31, 2017 and 2018, respectively. Creditors of the VIE have no recourse to the general credit of the primary beneficiary of the VIE, and such amounts have been parenthetically presented on the face of the consolidated balance sheets. The VIE holds certain assets, including data servers and related equipment for use in their operations. The VIE does not own any facilities except for the rental of certain office premises and data centers from third parties under operating lease arrangements. The VIE also holds certain value-added technology licenses, registered copyrights, trademarks and registered domain names, including the official website, which are also considered as revenue-producing assets. However, none of such assets was recorded on the Company’s consolidated balance sheets as such assets were all internally developed and expensed as incurred as they did not meet the capitalization criteria. The Company has not provided any financial or other support that it was not previously contractually required to provide to the VIE during the periods presented.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2	Summary of Significant Accounting Policies

Basis of presentation

The consolidated financial statements of the Company have been prepared in accordance with the generally accepted accounting principles of the United States (“U.S. GAAP”).

Principles of Consolidation

The consolidated financial statements include the financial statements of the Company, its subsidiaries, and the VIE. All significant intercompany transactions and balances have been eliminated upon consolidation.

Use of estimates

The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires the use of estimates and judgments that affect the reported amounts in the consolidated financial statements and accompanying notes. These estimates form the basis for judgments that management make about the carrying values of assets and liabilities, which are not readily apparent from other sources. Management base their estimates and judgments on historical information and on various other assumptions that they believe are reasonable under the circumstances. U.S. GAAP requires management to make estimates and judgments in several areas, including, but not limited to, those related to revenue recognition, collectability of accounts receivable, commitments, convertible notes, useful lives and impairment assessment of intangible assets, property and equipment, long-term investment, income taxes, valuation allowance for deferred tax assets, fair value change of derivative liability, and share-based compensation. These estimates are based on management's knowledge about current events and expectations about actions that the Company may undertake in the future. Actual results could differ from those estimates.

2	Summary of Significant Accounting Policies (continued)

Convenience translation

Translations of amounts from RMB into US$ for the convenience of the reader have been calculated at the exchange rate of RMB6.8755 per US$1.00 on December 31, 2018, as published on the website of the United States Federal Reserve Board. No representation is made that the RMB amounts could have been, or could be, converted into US$ at such rate.

Foreign currency translation

The functional currency of the Company and the Company’s subsidiary outside the PRC are US$. The Company’s PRC subsidiary and VIE adopted RMB as their functional currencies. The determination of the respective functional currency is based on the criteria stated in ASC 830, Foreign Currency Matters. The Company uses RMB as its reporting currency. The consolidated financial statements of the Company, are translated into RMB using the exchange rate as of the balance sheet date for assets and liabilities and average exchange rate for the year for income and expense items. Translation gains and losses are recorded in accumulated other comprehensive loss, as a component of shareholders’ deficit.

Transactions in currencies other than the functional currency are remeasured and recorded in the functional currency at the exchange rate prevailing on the transaction date.

Monetary assets and liabilities denominated in currencies other than the functional currency are remeasured into the functional currency at the rates of exchange prevailing at the balance sheet dates. Transaction gains and losses are recognized in the consolidated statements of comprehensive loss during the period or year in which they occur.

Cash and cash equivalents

Cash and cash equivalents primarily consist of cash and demand deposits which are highly liquid. The Company considers highly liquid investments that are readily convertible to known amounts of cash and with original maturities from the date of purchase of three months or less to be cash equivalents. All cash and cash equivalents are unrestricted as to withdrawal and use.

Restricted cash

Restricted cash represents cash granted by the government and designated only for the purchase of property and equipment for certain approved projects.

Accounts receivable and allowance for doubtful accounts

Accounts receivable are recorded at the realizable value amount, net of allowances for doubtful accounts. An allowance for doubtful accounts is recorded in the period when loss is probable based on many factors, including the age of the balance, the customer’s payment history and credit quality of the customers, current economic trends and other factors that may affect the Company’s ability to collect from customers. Bad debts are written off after all collection efforts have been exhausted.

Property and equipment, net

Property and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets or the remaining lease term, whichever is shorter. The estimated useful lives of property and equipment are as follows:


Computer equipment and servers		3 – 5 years
Office furniture and equipment		3 – 5 years
Leasehold improvements		over the shorter of lease terms or estimated useful lives of the assets

Expenditures for repair and maintenance are expensed as incurred. When assets are retired or otherwise disposed of, the cost and related accumulated depreciation are removed from their respective accounts, and any gain or loss on such sale or disposal is reflected in the consolidated statements of comprehensive loss.

2	Summary of Significant Accounting Policies (continued)

Intangible assets

Intangible assets with finite lives are carried at cost less accumulated amortization. Intangible assets represent purchased computer software. All intangible assets with finite lives are amortized using the straight-line method over the estimated economic lives, which are as follows:

Computer software and systems

1 – 3 years

Impairment of long-lived assets other than goodwill

The Company evaluates long-lived assets, such as property and equipment and purchased intangible assets with finite lives, for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable in accordance with ASC 360, Property, Plant and Equipment. When such events occur, the Company assesses the recoverability of the asset group based on the undiscounted future cash flow the asset group is expected to generate and recognizes an impairment loss when estimated undiscounted future cash flow expected to result from the use of the asset group plus net proceeds expected from disposition of the asset group, if any, is less than the carrying value of the asset group. If the Company identifies an impairment, the Company reduces the carrying amount of the asset group to its estimated fair value based on a discounted cash flow approach or, when available and appropriate, to comparable market values. The Company uses estimates and judgments in its impairment tests and if different estimates or judgments had been utilized, the timing or the amount of any impairment charges could be different. No impairment loss was recognized for the years ended December 31, 2016, December 31, 2017 and 2018, respectively.

Long-term investments

In accordance with ASC 325-20, Investments-Other: Cost Method Investments, the Company carries at cost its investments in investees which do not have readily determinable fair value and the Company does not have significant influence. The Company only adjusts for other-than-temporary declines in fair value and distributions of earnings that exceed the Company’s share of earnings since its investment.

Management regularly evaluates the impairment of the cost method investments based on performance and financial position of the investee as well as other evidence of market value. Such evaluation includes, but is not limited to, reviewing the investee’s cash position, recent financing, projected and historical financial performance, cash flow forecasts and financing needs. An impairment loss is recognized in earnings equal to the excess of the investment’s cost over its fair value at the balance sheet date of the reporting period for which the assessment is made. The fair value would then become the new cost basis of investment.

Deferred revenue and customer deposits

Deferred revenue consists of payments from customers in advance of revenue recognition. Customer deposits relate to customer’s unused balances that are refundable. Once this balance is utilized by the customer, the corresponding amount would be recognized as revenue.

Convertible notes

At the commitment date, the fees and expenses associated with the issuance of the convertible notes are recorded as a discount to the debt liability in accordance with ASU 2015-03. The convertible notes, which is the proceeds net of fees and expenses payable to the creditor and the fair value of the bifurcated derivative, will be accreted to the redemption value on the maturity date using the effective interest method over the estimated life of the debt instrument.

The Company has early adopted ASU 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, and ASU 2017-11, Accounting for Certain Financial Instruments with Down Round Features. ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The issuance cost of RMB8,436 (US$1,227) was currently presented as a direct deduction from the principal amount of the Convertible Notes on the consolidated balance sheet as of December 31, 2018. ASU 2017-11 no longer requires the Company to consider down round features when determining whether its embedded Conversion Option is indexed to its own stock.

2	Summary of Significant Accounting Policies (continued)

Value added taxes (“VAT”)

The Company presents VAT assessed by government authorities as reductions of revenues. Pursuant to the PRC tax legislation, VAT is generally imposed in lieu of business tax in the modern service industries, on a nationwide basis. VAT of 6% applies to revenue derived from the provision of certain modern services. The Company is allowed to offset the qualified input VAT paid on taxable purchases against the output VAT chargeable on the modern services provided.

Share split

On March 1, 2017, the board of directors approved a 1 for 10 share split. Share and per share amounts for common shares and contingently redeemable convertible preferred shares disclosed for all prior periods have been retroactively adjusted to reflect the effects of the share split.

Treasury shares

Treasury shares represent shares repurchased by the Company that are no longer outstanding and are held by the Company. Treasury shares are accounted for under the cost method per ASC 505-30 Treasury Stock. Under this method, repurchase of shares were recorded as treasury shares at historical purchase price. On November 20, 2018, the Board of Directors of the Company approved a plan to repurchase its own issued and outstanding American depositary shares (“ADSs”) up to an aggregate value of US$10 million from the open market (the “Repurchase Plan”). As of December 31, 2018, under the Repurchase Plan, the Company had repurchased an aggregate of 69,455 ADSs, representing 46,303 Class A common shares on the open market for a total cash consideration of US$468.

2	Summary of Significant Accounting Policies (continued)

Revenue recognition

The Company recognizes revenue once all of the following criteria have been met: (1) persuasive evidence of an arrangement exists; (2) services have been provided; (3) the price is fixed or determinable; and (4) collectability is reasonably assured.

Data solutions

The Company generates data solutions revenues primarily by creating and delivering targeted marketing and other vertical data solutions. Targeted marketing revenue is generated by the Company providing an integrated marketing campaign to advertisers mainly through the Company’s Xiaoguotong marketing platform, which is built upon the Company’s multi-dimensional mobile device dataset. The Company generally will create, design, develop and optimize the advertising content for its advertisers. The advertisements are displayed on a wide spectrum of reputable publishers, through bidding for advertisement slots using rates directly negotiated with the various publishers.

The arrangements with advertisers are evidenced through contractual agreements that stipulate the types of advertising to be delivered, the timing and the pricing. Advertisers pay for targeted advertisements based on the number of clicks and downloads taken by the users. Revenue is recognized in the period in which the user performs the action the advertiser contracted the Company for.

The Company recognizes revenue on a gross basis as the primary obligor, as it uses its own platform’s mobile device dataset with its comprehensive demographic targeting ability to accurately pinpoint the specific mobile devices that is most suitable for the customer’s ads. Additionally, the Company has pricing latitude, has discretion in selecting publishers whose advertisement slots will be purchased, is highly involved in the determination of service specifications and bears credit risk. Based on the advertiser’s preference to avoid lower quality publishers, the Company may recommend a specific reputable online media network to certain advertisers. After pinpointing the specific mobile devices that are most suitable for the customer’s ads using its mobile device dataset, it bids for the available advertising slots on the network and then places the advertisement.

Developer services

The Company enters into agreements with its customers to provide push notification and instant messaging (collectively “notification services”). Under the terms of the contractual agreements of notification services, the Company provides its customers with access to its notification services platform over the specified period. This enables customers to send notifications and messages to users. Revenue from notification services is recognized using a specific performance method.

Costs of revenues

Cost of revenues consists primarily of depreciation, labor, bandwidth costs and purchasing of advertising inventory. The Company incurs various sales tax and surcharges such as, city construction tax and education surcharges and cultural development fee in connection with the services provided. In accordance with ASC subtopic 605-45, Revenue Recognition, Principal Agent Considerations (“ASC 605-45”), the Company includes the sales tax and surcharges incurred in cost of revenues.

Research and development

Research and development expenses are primarily incurred in the development of new services, new features, and general improvement of the Company’s technology infrastructure to support its business operations. Research and development costs are expensed as incurred unless such costs qualify for capitalization as software development costs. In order to qualify for capitalization, (i) the preliminary project should be completed, (ii) management has committed to funding the project and it is probable that the project will be completed and the software will be used to perform the function intended, and (iii) it will result in significant additional functionality in the Company’s services. No research and development costs were capitalized during any of the years presented as the Company has not met all of the necessary capitalization requirements.

Advertising expense

Advertising expenses, including promotion expenses, are charged to “sales and marketing expenses” as incurred. Advertising expenses amounted to RMB10,377, RMB5,277 and RMB6,697 (US$974) for the year ended December 31, 2016, 2017 and 2018, respectively.

2	Summary of Significant Accounting Policies (continued)

Other income

Other income represents government grants and profit sharing program with Depositary Bank related to ADSs depositary. Government grants are recognized when there is reasonable assurance that the Company will comply with the attached conditions. When the grant relates to an expense item, it is recognized on a systemic basis in the consolidated statement of comprehensive loss over the period necessary to match the grant to the related costs. Where the grant relates to an asset acquisition, it is recognized in the consolidated statements of comprehensive loss in proportion to the depreciation of the related assets. Profit sharing program is recognized over five-year period as specified in the contract based on certain parameters.

Government grants

Government grants primarily consist of financial grants received from provincial and local governments for operating a business in their jurisdictions and compliance with specific policies promoted by the local governments. For certain government grants, there are no defined rules and regulations to govern the criteria necessary for companies to receive such benefits, and the amount of financial subsidy is determined at the discretion of the relevant government authorities. The government grants of non-operating nature with no further conditions to be met are recorded as non-operating income in “Other income, net” when received. The government grants with certain operating conditions are recorded as “deferred income” when received and will be recorded as operating income when the conditions are met.

Operating leases

Leases where substantially all the risks and rewards of ownership of assets remain with the lessor are accounted for as operating leases. Rentals applicable to such operating leases are recognized on a straight-line basis over the lease term. The Company had no capital leases during the years presented.

Employee defined contribution plan

Full time employees of the Company in the PRC participate in a government mandated defined contribution plan pursuant to which certain pension benefits, medical care, unemployment insurance, employee housing fund, and other welfare benefits are provided to employees. Chinese labor regulations require that the Company make contributions to the government for these benefits based on a certain percentage of the employee’s salaries. The Company has no legal obligation for the benefits beyond the contributions. The total amount that was expensed as incurred was RMB5,455, RMB12,121 and RMB11,301 (US$1,644) for the year ended December 31,2016, December 31, 2017 and 2018, respectively.

Income taxes

The Company accounts for income taxes using the liability approach and recognizes deferred tax assets and liabilities for the expected future consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are recognized on the basis of the temporary differences that exist between the tax basis of assets and liabilities and their reported amounts in the consolidated financial statements using enacted tax rates in effect for the year end in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in earnings. Deferred tax assets are reduced by a valuation allowance through a charge to income tax expense when, in the opinion of management, it is more-likely-than-not that a portion of or all of the deferred tax assets will not be realized. The Company evaluates the potential for recovery of deferred tax assets by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The components of the deferred tax assets and liabilities are classified as non-current.

The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of the benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained (defined as a likelihood of more than fifty percent of being sustained upon an audit, based on the technical merits of the tax position), the tax position is then assessed to determine the amount of benefits to recognize in the consolidated financial statements. The amount of the benefits that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. Interest and penalties on income taxes will be classified as a component of the provisions for income taxes.

2	Summary of Significant Accounting Policies (continued)

Income taxes (continued)

The Company evaluated its income tax uncertainty under ASC 740. ASC 740 clarifies the accounting for uncertainty in income taxes by prescribing the recognition threshold a tax position is required to meet before being recognized in the financial statements. The Company elects to classify interest and penalties related to an uncertain tax position, if and when required, as part of income tax expense in the consolidated statements of comprehensive loss.

The Company did not recognize any income tax due to uncertain tax position or incur any interest and penalties related to potential underpaid income tax expenses during the years presented.

Share-based compensation

In accordance with ASC 718, Compensation-Stock Compensation, the Company determines whether an award granted to its employees should be classified and accounted for as a liability award or equity award. The Company’s share-based compensation to its employees which were classified as equity awards were recognized in the consolidated statements of comprehensive loss based on the grant date fair value. The Company’s share-based compensation to its employees which were classified as liability awards were recognized in the consolidated statements of comprehensive loss based on the fair value at each reporting date until settlement. The Company early adopted Accounting Standard Update (“ASU”) ASU 2016-09—Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting and elected to account for forfeitures as they occur.

Fair value measurements

Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and the market-based risk measurement or assumptions that market participants would use when pricing the asset or liability.

Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

Level 1-Quoted prices in active markets for identical assets or liabilities.

Level 2-Observable inputs other than quoted prices in active markets, quoted prices for identical or similar assets and liabilities in inactive markets or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3-Inputs that are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability.

The carrying amounts of financial assets and liabilities, such as cash equivalents, restricted cash, accounts receivable, other receivables within prepaid expenses and other current assets, balances with related parties, accounts payable, and other payables with accrued liabilities and other current liabilities, approximate their fair values because of the short maturity of these instruments. The carrying amounts of restricted cash (non-current) approximate its fair value since it bears interest rates which approximate market interest rates.

Comprehensive loss

Comprehensive loss is defined as the increase or decrease in equity of the Company during a year from transactions and other events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Accumulated other comprehensive loss of the Company includes the foreign currency translation adjustments.

2	Summary of Significant Accounting Policies (continued)

Loss per share

In accordance with ASC 260, Earning per Share, basic loss per share is computed by dividing net loss attributable to common shareholders by the weighted average number of common shares outstanding during the period using the two-class method. Under the two-class method, net income is allocated between common shares based on dividends declared (or accumulated) and participating rights in undistributed earnings as if all the earnings for the reporting period had been distributed. For the year ended December 31, 2018, the two-class method is applicable because the Company has two classes of common shares outstanding, Class A and Class B common shares, respectively. The participating rights (liquidation and dividend rights) of the holders of the Company’s Class A and Class B common shares are identical, except with respect to voting. As a result, and in accordance with ASC 260, as the liquidation and dividend rights are identical, the undistributed loss is allocated on a proportionate basis.

Diluted loss per share is computed by dividing net loss attributable to common shareholders as adjusted for the effect of dilutive common equivalent shares, if any, by the weighted average number of common and dilutive common equivalent shares outstanding during the years. Common equivalent shares consist of the common shares issuable upon the conversion of the Company’s contingently redeemable convertible preferred shares and the convertible senior notes using the if-converted method and common shares, including partially paid shares, issuable upon the exercise of the share options, using the treasury stock method. Common share equivalents are excluded from the computation of diluted loss per share if their effects would be anti-dilutive.

Concentration of risks

Concentration of credit risk

Financial assets that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, short-term investments and accounts receivable.

The Company places its cash and cash equivalents with reputable financial institutions which have high-credit ratings. As of December 31, 2017 and 2018, the aggregate amount of cash and cash equivalents and restricted cash of RMB82,609 and RMB331,374 (US$48,198), respectively, were held at major financial institutions located in the PRC, and US$19,232 and US$35,678 (RMB245,303), respectively, were deposited with major financial institutions located outside the PRC. There has been no recent history of default related to these financial institutions. The Company continues to monitor the financial strength of the financial institutions. The Company manages credit risk of accounts receivable through ongoing monitoring of the outstanding balances.

Concentration of suppliers

Approximately 81.3% and 50.9% of advertising costs were paid to three suppliers for the year ended December 31, 2017 and 2018, respectively.

Business and economic risk

The Company believes that changes in any of the following areas could have a material adverse effect on the Company’s future consolidated financial position, results of operations or cash flows; changes in the overall demand for services; competitive pressures due to new entrants; advances and new trends in new technologies and industry standards; changes in certain strategic relationships; regulatory considerations and risks associated with the Company’s ability to attract employees necessary to support its growth. The Company’s operations could also be adversely affected by significant political, regulatory, economic and social uncertainties in the PRC.

Currency convertibility risk

Substantially all of the Company’s businesses are transacted in RMB, which is not freely convertible into foreign currencies. All foreign exchange transactions take place either through the People’s Bank of China (“PBOC”) or other authorized financial institution at exchange rates quoted by PBOC. Approval of foreign currency payments by the PBOC or other regulatory institutions requires submitting a payment application form together with suppliers’ invoices and signed contracts.

Foreign currency exchange rate risk

The functional currency and the reporting currency of the Company are the US$ and the RMB, respectively. On June 19, 2010, the PBOC announced the end of the RMB’s de facto peg to the US$, a policy which was instituted in late 2008 in the face of the global financial crisis, to further reform the RMB exchange rate regime and to enhance the RMB’s exchange rate flexibility. On March 15, 2014, the People’s Bank of China announced the widening of the daily trading band for RMB against US$. The appreciation of the US$ against RMB was approximately 4.79% in 2018. Most of the Company’s revenues and costs are denominated in RMB, while a portion of cash and cash equivalents, short-term investments, and accounts payable are denominated in US$. Any significant revaluation of RMB may materially and adversely affect the Company’s consolidated revenues, earnings and financial position in US$.

2	Summary of Significant Accounting Policies (continued)

Segment information

The Company’s chief operating decision maker is the Chief Executive Officer, who makes resource allocation decisions and assesses performance based on the consolidated financial results. As a result, the Company has only one reportable segment.

As the Company generates substantially most of its revenues in the PRC, no geographical segments is presented.

Recently issued accounting pronouncements

As a company with less than US$1.07 billion in revenue for the last fiscal year, the company qualifies as an “emerging growth company” pursuant to the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). An emerging growth company may take advantage of specified reduced reporting and other requirements that are otherwise applicable generally to public companies. These provisions include a provision that an emerging growth company does not need to comply with any new or revised financial accounting standards until such date that a private company is otherwise required to comply with such new or revised accounting standards. The Company will take advantage of the extended transition period.

In May 2014, the Financial Accounting Standard Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606). The guidance substantially converges final standards on revenue recognition between the FASB and the International Accounting Standards Board providing a framework on addressing revenue recognition issues and, upon its effective date, replaces almost all existing revenue recognition guidance, including industry-specific guidance, in current U.S. GAAP.

The core principle of the guidance is that an entity should recognize revenues to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this core principle, an entity should apply the following steps:

Step 1: Identify the contract(s) with a customer.

Step 2: Identify the performance obligations in the contract.

Step 3: Determine the transaction price.

Step 4: Allocate the transaction price to the performance obligations in the contract.

Step 5: Recognize revenue when (or as) the entity satisfies a performance obligation.

In August 2015, the FASB issued its final standard formally amending the effective date of the new revenue recognition guidance. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2018, including interim periods beginning after January 1, 2020. As an “emerging growth company,” or EGC, the Company has elected to take advantage of the extended transition period provided in the Securities Act Section 7(a)(2)(B) for complying with new or revised accounting standards applicable to private companies. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customer - Principal versus Agent Considerations (“ASU 2016-08”), which clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customer - Identifying Performance Obligations and Licensing, which clarifies guidance related to identifying performance obligations and licensing implementation guidance contained in ASU 2014-09. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers - Narrow-Scope Improvements and Practical Expedients (“ASU 2016-12”), which addresses narrow-scope improvements to the guidance on collectability, non-cash consideration and completed contracts at transition and provides practical expedients for contract modifications at transition and an accounting policy election related to the presentation of sales taxes and other similar taxes collected from customers. The effective dates for these amendments are the same as the effective date of ASU 2014-09. Early adoption is permitted.

The Company will adopt ASU 2014-09 for the annual reporting periods beginning January 1, 2019, using the modified retrospective method. The cumulative effect of initially applying the new standard will be recognized on the day of initial application and prior periods will not be retrospectively adjusted. The Company’s implementation efforts are substantially complete. The Company also estimate that there will not be a material impact to the beginning balance of retained earnings.

2	Summary of Significant Accounting Policies (continued)

Recently issued accounting pronouncements (continued)

In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10). The amendments require all equity investments to be measured at fair value with changes in the fair value recognized through net income (other than those accounted for under equity method of accounting or those that result in consolidation of the investee). The amendments also require an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instruments-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. In addition, the amendments in this ASU eliminate the requirement to disclose the fair value of financial instruments measured at amortized cost for entities that are not public business entities. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2018, including interim periods after December 15, 2019. The Company is in the process of evaluating the impact of the adoption of this guidance on its consolidated financial statements.

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This ASU modifies existing guidance for off-balance sheet treatment of a lessees’ operating leases by requiring lessees to recognize lease assets and lease liabilities, whilst, lessor accounting is largely unchanged. The amendments in this ASU are effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements (“ASU 2018-11”), which provides another transition method in addition to the existing transition method by allowing entities to initially apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption consistent with preparers’ requests. The amendments in this Update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years for public entities. The Company is in the process of evaluating the impact of adoption of this guidance on its consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This ASU is intended to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. This ASU requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This ASU requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of the Company’s portfolio. These disclosures include qualitative and quantitative requirements that provide additional information about the amounts recorded in the financial statements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2020, including interim periods within fiscal years beginning after December 15, 2021. In November 2018, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses (“ASU 2018-19”), which amends ASU 2016-13 to clarify that receivables arising from operating leases are not within the scope of Subtopic 326-20, and instead, impairment of such receivables should be accounted for in accordance with Topic 842, Leases. ASU 2016-13 and ASU 2018-19 are effective for fiscal years and interim periods within those years beginning after December 15, 2019, with early adoption permitted as of the fiscal years beginning after December 15, 2018. An entity will apply the amendments in these updates through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). The Company is currently evaluating the impact this guidance will have on its consolidated financial statements when adopted. The Company is in the process of evaluating the impact of adoption of this guidance on its consolidated financial statements.

In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This ASU reduces the existing diversity in practice in financial reporting across all industries by clarifying certain existing principles in ASC 230, Statement of Cash Flows (“ASC 230”), including providing additional guidance on how and what an entity should consider in determining the classification of certain cash flows. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. The Company has early adopted this standard.

In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. This ASU requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This ASU does not provide a definition of restricted cash or restricted cash equivalents. The amendments are effective for fiscal years beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2019. The Company has early adopted this standard.

2	Summary of Significant Accounting Policies (continued)

Recently issued accounting pronouncements (continued)

In February 2017, the FASB issued ASU No. 2017-05, Other income—Gains and Losses from the Derecognition of Nonfinancial Assets, which clarifies that a financial asset is within the scope of Subtopic 610-20 if it meets the definition of an in substance nonfinancial asset. The amendments in this update also clarify that nonfinancial assets within the scope of Subtopic 610-20 may include nonfinancial assets transferred within a legal entity to a counterparty. This standard is effective for annual reporting periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. The Company is in the process of evaluating the impact of adoption of this guidance on its consolidated financial statements.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, including, among other changes, the consideration of costs and benefits when evaluating disclosure requirements. For public companies, the amendments are effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual periods. Early adoption is permitted. The Company is in the process of evaluating the impact of adoption of this guidance on its consolidated financial statements.

Accounts Receivable, Net

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts receivable, net

3	Accounts receivable, net

	As of December 31,
	2017			2018
	RMB			RMB			US$
Accounts receivable		53,056			151,219			21,994
Less: allowance for doubtful accounts		(3,462	)		(9,308	)		(1,354	)
Total accounts receivable, net		49,594			141,911			20,640

The following table presents the movement in the allowance for doubtful accounts:

	As of December 31,
	2017		2018
	RMB		RMB			US$
Balance at beginning of year		1,035		3,462			504
Provisions		2,427		6,389			929
Write-offs		—		(543	)		(79	)
Balance at end of year		3,462		9,308			1,354

Prepayment and Other Current Assets

12 Months Ended

Dec. 31, 2018

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Prepayment and other current assets

4	Prepayment and other current assets

Prepayment and other current assets consist of the following:

	As of December 31,
	2017		2018
	RMB		RMB		US$
Prepaid media cost		19,610		54,937		7,990
Prepaid service fee		1,762		6,804		989
Others		12,856		18,837		2,740
Total prepayment and other current assets		34,228		80,578		11,719